Hybrid bearing assembly with rolling elements and plain bearing

ABSTRACT

A bearing assembly includes an outer race having an inner surface defining a concave contour and an inner race positioned in the outer race. The inner race has an inner surface defining a bore therethrough and an outer surface defining at least one groove circumscribing the outer surface. A plurality of rolling elements is rollably located in the groove and is in rolling contact with the inner surface of the outer race. A lubricious liner has an inner liner-surface and an exterior liner-surface, the exterior liner-surface being disposed on the inner surface defining the bore. The lubricious liner has a modulus of compression of a magnitude sufficient to allow misalignment of the inner liner-surface relative to the exterior liner-surface in response to a force applied thereto.

CROSS REFERENCE TO RELATED APPLICATIONS

The instant application is a continuation application of and claimspriority benefit to U.S. application Ser. No. 14/438,785, entitled“HYBRID BEARING ASSEMBLY WITH ROLLING ELEMENTS AND PLAIN BEARING,” filedon Apr. 27, 2015, which is a national stage application of, and claimspriority benefit to PCT Application No. PCT/US13/38626, entitled “HYBRIDROLLING ELEMENT AND PLAIN BEARING,” filed on Apr. 29, 2013, which is aPCT application of and claims priority to U.S. Provisional PatentApplication No. 61/640,302, entitled “HYBRID ROLLING ELEMENT AND PLAINBEARING,” filed on Apr. 30, 2012, the entirety of each of which isincorporated by reference herein.

TECHNICAL FIELD

The present invention is directed to bearings and, more particularly, tohybrid bearings for use in fixed wing aircraft flap hinge arms.

BACKGROUND

The wings of a fixed wing aircraft typically employ ailerons and flapsthat are mounted on hinges longitudinally along the wings. Ailerons areflight control surfaces that are hinged to the trailing edges of thewing and are independently movable up and down to deflect airflow awayfrom the wing, thereby altering the lift on the wing and controlling theroll moment of the aircraft as well as allowing the plane to bank. Flapsare flight control surfaces that are also hinged to the trailing edgesof the wings but are movable in tandem up or down. Angling the flapsdown to deflect airflow down and away from the wing reduces the flightspeed and allows the angle of descent to be increased without increasingair speed. In larger aircraft, the flaps are also generally extendableoutward from the trailing edges.

In using the flaps, however, the curvature of the wing is increased.Because the flaps are mounted along the wings in the directions in whichthe wings extend, increasing the curvature of a wing causes stress atthe points at which the flaps are coupled to the wing. Bearings are usedat these points in conjunction with linkages to enable the flaps to beextended and angled in response to pilot control. Placing stresses onthe points at which the flaps are coupled to the wings may compromisethe operation of the bearings, which in turn may affect the positioningof the flaps and operation of the aircraft.

U.S. Patent Application Publication No. 2011/0220762 discloses anaircraft wing that includes a wing structure, a slat panel mounted on atrack, and an actuator mechanism on the wing structure coupled to thetrack for moving the slat panel between a deployed position and aretracted position. Track roller bearings on the wing structurerotatably contact the track, and side roller bearings on the wingstructure rotatably contact at least one side of the track. In anotherconfiguration, the actuator mechanism includes a shaft rotatably mountedon the wing structure, an actuator arm coupled to the track by a bearinglinkage, and an actuator lever coupled to the shaft by a bearing linkageand to the actuator arm by a bearing linkage. At least one bearinglinkage includes a spherical plain bearing. In addition, U.S. PatentPublication No. 2011/067509, German Patent Application No. 197 50 113,U.S. Pat. No. 1,457,584, U.S. Patent Publication No. 2012/058923,European Patent Application No. 0 843 106 and International PatentApplication Publication No. WO 2012/080983 are also relevant to thepresent application.

SUMMARY

In one aspect, the present invention resides in a bearing assemblycomprising: an outer race having an inner surface defining a concavecontour; an inner race positioned in the outer race, the inner racehaving an inner surface defining a bore therethrough and an outersurface defining at least one groove circumscribing the outer surface; aplurality of rolling elements rollably located in the at least onegroove and in rolling contact with the inner surface of the outer race;and a lubricious liner having an inner liner-surface and an exteriorliner-surface, the exterior liner-surface being disposed on the innersurface defining the bore, the lubricious liner having a modulus ofcompression of a magnitude sufficient to allow misalignment of the innerliner-surface relative to the exterior liner-surface in response to aforce applied thereto.

In another aspect, the present invention resides in a bearing assemblycomprising: an outer race having an inner surface defining a concavecontour; an inner race positioned in the outer race, the inner racehaving an inner surface defining a bore therethrough and an outersurface defining at least one groove circumscribing the outer surface; aplurality of rolling elements rollably located in the at least onegroove and in rolling contact with the inner surface of the outer race;and a lubricious liner having a coefficient of friction of a magnitudesufficient to prevent relative motion between the inner race and a shaftextending through the bore of the inner race during a first operatingcondition and to allow relative motion between the inner race and theshaft during a second operating condition.

In another aspect, the present invention resides in a flap hinge arm ofa fixed wing aircraft, comprising: an arm; a connecting rod pivotallyconnected to the arm and pivotally connectable to a flap; and a bearingassembly positioned on the arm and connectable to a wing of the fixedwing aircraft, the bearing assembly comprising, an outer race having aninner surface defining a concave contour; an inner race positioned inthe outer race, the inner race having an inner surface defining a boretherethrough and an outer surface defining at least one groovecircumscribing the outer surface; a plurality of rolling elementsrollably located in the at least one groove and in rolling contact withthe inner surface of the outer race; and a lubricious liner having aninner liner-surface and an exterior liner-surface, the exteriorliner-surface being disposed on the inner surface defining the bore, thelubricious liner having a modulus of compression of a magnitudesufficient to allow misalignment of the inner liner-surface relative tothe exterior liner-surface in response to a force applied thereto, and acoefficient of friction of a magnitude sufficient to prevent relativemotion between the inner race and a shaft extending through the bore ofthe inner race during a first operating condition and to allow relativemotion between the inner race and the shaft during a second operatingcondition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side sectional view of a bearing assembly, of the presentinvention.

FIG. 2A presents one embodiment of the bearing assembly of FIG. 1 in afirst operating condition.

FIG. 2B presents the bearing assembly of FIG. 2A in a second operatingcondition.

FIG. 3A presents another embodiment of the bearing assembly of FIG. 1 ina first operating condition.

FIG. 3B presents the bearing assembly of FIG. 3A in a second operatingcondition.

FIG. 4A presents another embodiment of the bearing assembly of FIG. 1 ina first operating condition.

FIG. 4B presents the bearing assembly of FIG. 4A in a second operatingcondition.

FIG. 5 is a side sectional view of another embodiment of a bearingassembly of the present invention.

FIG. 6 is a side sectional view of yet another alternate embodiment of abearing assembly of the present invention.

FIG. 7 is a side sectional view of yet another alternate embodiment of abearing assembly of the present invention.

FIG. 8 is a side sectional view of yet another alternate embodiment of abearing assembly of the present invention.

FIG. 9 is a side view of a flap hinge arm of a fixed wing aircraft inwhich the bearing assembly of FIG. 1 or FIGS. 5-8 is installed.

FIG. 10 is a front sectional view of the arm and bearing assembly of theflap hinge arm of FIG. 9.

FIG. 11 is a side sectional view of a wing of a fixed wing aircraftincorporating the flap hinge arm of FIG. 9 in an extended position.

FIG. 12 is a side sectional view of a wing of a fixed wing aircraftincorporating the flap hinge arm of FIG. 9 in a retracted position.

DETAILED DESCRIPTION

As shown in FIG. 1, an airframe control bearing assembly for use with anaircraft flap hinge arm is designated generally by the number 10 and ishereinafter referred to as “bearing assembly 10.” Bearing assembly 10 isa hybrid bearing that combines the misalignment (swivel action)capabilities of a plain spherical bearing and the rolling element aspectof an airframe control bearing, with a third degree of freedom whichincludes axial sliding of the bearing on a self-lubricated surface thusallowing for the accommodation of a greater degree of misalignment(e.g., rotational, tilt or cocking, and axial sliding) as compared toconventional bearings used in flap hinge arms. In particular, the rangeof motion of oscillation can be up to about 45 degrees. The presentinvention is not limited to an oscillation range of motion of about 45degrees, however, as the oscillation of the bearing assembly may begreater than about 45 degrees.

In the illustrated embodiment, the bearing assembly 10 comprises aninner race 12 concentrically positioned in an outer race 14. A pluralityof rolling elements or balls 16 are located between and rollingly engagethe inner and outer races, 12 and 14 respectively. The present inventionis not limited to the use of balls 16, however, as any suitable rollingelement may be employed. The inner race 12 is defined by an innersurface 18 and an outer surface 20. The outer surface 20 includes twogrooves 17 that circumscribe the outer surface 20. At least a portion ofthe balls 16 rollingly engage each of the grooves 17. As illustrated,the balls 16 are arranged in two staggered rows such that each ball isstaggered relative to the next adjacent ball. The inner surface 18defines a bore 22 extending through the inner race 12, the bore beinglocated substantially concentrically about an axis A.

In the illustrated embodiment, the outer race 14 is a ring that isdefined by an inner surface 26 having a spherically concave contour andan outer surface 28. The concave contour of the outer race inner surface26 allows for the inner race 12 to be misaligned relative to the outerrace 14 by up to about 45 degrees to accommodate the oscillation rangeof motion of bearing assembly 10 as described above. The balls 16rollingly engage the inner surface 26. The outer surface 28 is suitablyconfigured to facilitate the mounting of the bearing assembly 10 in aflap hinge arm. Upon incorporation of the bearing assembly 10 into theflap hinge arm, the outer race 14 and the inner race 12 rotateindependently of each other. While the outer race 14 has been shown anddescribed as being a ring, the present invention is not limited in thisregard as the outer race can assume any practical shape or be integralwith the flap hinge arm into which the bearing assembly 10 is installedwithout departing from the broader aspects of the present invention.

The bearing assembly 10 includes a seal 30 positioned across theinterface of the inner race 12 and the outer race 14 to inhibit theingress of debris and contaminants into the bearing assembly. Retainingrings 32 are employed on the outer race 14 on opposing sides of theseals 30 to secure the seals in place. The bearing assembly 10 mayinclude two seals 30 positioned generally opposite one another onopposing sides of the bearing assembly.

The balls 16 may be made from a steel or an alloy steel. For example,the balls 16 may be made from a stainless steel such as 440C (AMS 5880or 5618), 52100 (AMS 6440), or Corrosion Resistant Nitrogen (“CREN”)Steel (e.g., Cronidur 30® (available from Progressive Alloy SteelsUnlimited of Las Vegas, Nev.), AMS 5898, or other suitable CREN whenavailable), or the like. It is also contemplated that the balls 16 maybe made from other materials that are sufficiently hard or can besufficiently hardened through heat treatment.

Both the inner race 12 and the outer race 14 may be made from a steel oran alloy steel, including, but not limited to, a stainless steel such as440C (AMS 5880 or 5618), AMS 5655 solution nitride (CREN), 52100 (AMS6440), Cronidur 30® (AMS 5898), or Aubert and Duvall XD15NW®, or anothersuitable material.

The bearing assembly 10 also includes a self-lubricating coatingcomposition bonded to the inner surface 18 defining the bore 22 to forma lubricious liner 36 having an inner liner-surface 36B and an exteriorliner-surface 36A. As illustrated in FIG. 1, the bearing assembly 10 ismounted on a shaft 23 which extends through the bore 22. The shaft 23 issubstantially cylindrical and defines an exterior surface 25. Thelubricious liner 36 is disposed between the shaft 23 and the bore 22.The lubricious liner inner liner-surface 36B engages the exteriorsurface 25 of the shaft 23; and the lubricious liner exteriorliner-surface 36A engages the inner surface 18 defining the bore 22. Theshaft 23 is press fit into the bore 22 so that during normal operationof the bearing assembly 10 the shaft 23 is fixed relative to the innerrace 12 and there is essentially no slippage between the lubriciousliner 36 and the exterior surface 25. As shown in FIGS. 2A and 2B, thelubricious liner 36 has a continuous annular shape. As shown in FIGS. 3Aand 3B the lubricious liner 36 has an axial length L. The interiorliner-surface 36B engages the exterior surface 25 of the shaft 23,continuously and entirely circumferentially around the shaft 23 (e.g.,uninterrupted), along the axial length L of the lubricious liner 36. Theexterior liner-surface 36A engages the inner surface 18, continuouslyand entirely circumferentially around the inner surface 18 (e.g.,uninterrupted), along the axial length L of the lubricious liner 36.

The coefficient of friction of the lubricious liner 36 is of a magnitudesufficient to prevent relative motion between the inner race 12 and theshaft 23 extending through the bore 22 during a first operatingcondition and to allow relative motion between the inner race 12 and theshaft 23 during a second operating condition, both in a radial directionand in an axial direction. For example, during a first operatingcondition, referred to herein as “normal operation,” as shown in FIG.2A, a first operating torque t1 is transmitted to the outer race 14which rotates in relation to inner race 12 by action of the balls 16. Asecond operating torque t2 is transmitted to the lubricious liner 36 andcorrespondingly to the shaft 23. The lubricious liner 36 has a staticcoefficient of friction of a sufficient magnitude to maintain the shaft23 in a substantially fixed relation to the inner race 12 and thelubricious liner 36 during normal operation when the first operatingtorque is in the range up to torque t1 and the second operating torqueis in the range up to torque t2. For illustrative purposes, an indicatorI1 indicates a first position of bearing 10 during normal operationwherein the indicator I1 of the shaft 23, lubricious liner 36, innerrace 12, and outer race 14 align. Upon torque t1 being transmitted tobearing 10, the outer race rotates as indicated by an indicator I2 whilethe indicator I1 of the shaft 23, lubricious liner 36 and inner race 12remains stationary.

In contrast, during a second operating condition, referred to herein as“anomalous operation,” as shown in FIG. 2B, a third operating torque, oran anomalous operation torque t3 in excess of normal operating torquet1, is transmitted to the outer race 14 which rotates in relation toinner race 12 by action of the balls 16. A fourth operating torque, oran anomalous operation torque t4 in excess of normal operating torquet2, is transmitted to the inner race 12, lubricious liner 36 andcorrespondingly to the shaft 23. The coefficient of friction of thelubricious liner 36 is of a sufficient magnitude to enable rotationalsliding engagement between the exterior surface 25 of shaft 23 and thelubricious liner 36 when friction between the inner race 12 and theouter race 14 exceeds a predetermined magnitude thereby causinganomalous operation. For illustrative purposes, an indicator I3indicates a first position of bearing 10 during anomalous operationwherein the indicator I3 of the shaft 23, lubricious liner 36, innerrace 12, and outer race 14 align. Upon torque t3 being transmitted tobearing 10, the outer race rotates as indicated by an indicator 15, andthe shaft 23 also rotates in relation to the lubricious liner 36 andinner race 12 as indicated by an indicator I4. In such a case, outerrace 14 may rotate less than rotation under normal operation (i.e., theouter race 14 is rotating under anomalous operation), or the outer race14 may remain stationary in relation to the inner race 12. If rotationof the outer race 14 relative to the inner race 12 is impeded by seizureof the balls 16, the inner race 12 and lubricious liner 36 will moverelative to the shaft 23 and the exterior surface 25 slides relative tothe lubricious liner 36. The lubricious liner 36 is operable to engage amating surface and to enable sliding engagement with the mating surfacewhen torque required to rotate the outer race 14 relative to the innerrace 12, exceeds a predetermined value.

Under normal operation, an axial force defined as equal to or less thanan axial holding force is transmitted to the interface of the lubriciousliner 36 and the shaft 23 wherein lubricious liner 36 is operable toengage and retain shaft 23. Under anomalous operation, an axial forcegreater than the axial holding force, defined as an axial break-awayforce, is transmitted to the interface of the lubricious liner 36 andthe shaft 23 wherein lubricious liner 36 is operable to permit axialsliding or shifting of shaft 23. In one embodiment, the predeterminedvalue of a torque applied to bearing 10 is normal operating torque t1,and anomalous operation torque t3 is in a range of magnitude of about1.5 normal operating torque t1. In another embodiment, the predeterminedvalue of a torque applied to bearing 10 is normal operating torque t1,and anomalous operation torque t3 is in a range of magnitude of about1.25 normal operating torque t1. In another embodiment, thepredetermined value of a torque applied to bearing 10 is normaloperating torque t1, and anomalous operation torque t3 is in a range ofmagnitude of about 1.1 normal operating torque t1. Furthermore, thelubricious liner 36 also functions as a fail-safe mechanism by allowingthe shaft to rotational slip in the bore 22 if the bearing were toseize.

As also shown in FIG. 3A, the bearing assembly 10 is mounted on theshaft 23 which is a least partially disposed in the bore 22 and exteriorsurface 25 of shaft 23 engages the lubricious liner 36. The lubriciousliner 36 reduces friction between exterior surface 25 of shaft 23received in or through the bore 22 and the inner surface 18 defining thebore particularly when forces (for example, as a result of wing bendingor thermal differentials) act on the shaft in directions indicated bythe arrow R and parallel to an axis B. The bearing assembly 10 may alsotranslate along the shaft to some degree with reduced friction becauseof the presence of the lubricious liner 36. As described above, thecoefficient of friction of the lubricious liner 36 is of a magnitudesufficient to prevent relative motion between the inner race 12 and theshaft 23 extending through the bore 22 during a first operatingcondition and to allow relative motion between the inner race 12 and theshaft 23 during a second operating condition. As shown in FIG. 3B, whenforces act on shaft 23 in directions R parallel to axis B during asecond operating condition, exterior surface 25 of shaft 23 engages thelubricious liner 36 and moves in the direction R a distance Y inrelation to inner surface 18 of bore 22. Distance Y can be representedin relation to an outer diameter D of shaft 23. In one embodiment,distance Y is in the range of about 0.25 D. In one embodiment, distanceY is in the range of about 0.5 D. In one embodiment, distance Y is inthe range of about D. In one embodiment, distance Y is in the range ofabout 2 D. The lubricious liner 36 also removes the need for theincorporation of a galvanic barrier on the bearing assembly 10 or theshaft in the event that the surface defining the bore 22 is a differentmaterial than the material of the shaft.

As shown in FIGS. 4A and 4B, the lubricious liner 36 has a modulus ofcompression of a magnitude sufficient to allow misalignment (e.g., axialangular misalignment) of the lubricious liner inner liner-surface 36Bdisposed on the exterior surface 25 of the shaft 23 relative to thelubricious liner exterior liner-surface 36A disposed on the innersurface 18 defining the bore 22 in the inner race 12 in the directionsgenerally indicated by the arrow N in response to a force appliedthereto. As such, lubricious liner 36 provides for an axial angularmisalignment of the shaft 23 in relation to the inner race 12. Thebearing assembly 10 is mounted on the shaft 23 which is a leastpartially disposed in the bore 22 and exterior surface 25 of shaft 23engages the lubricious liner 36. The lubricious liner 36 has a modulusof compression of a magnitude sufficient to maintain the lubriciousliner inner liner-surface 36B in a substantially fixed relation to thelubricious liner exterior liner-surface 36A during normal operation suchshaft 23, lubricious liner 36 and inner race 12 are substantiallyconcentric about a central axis B.

Upon application of a force or load in the direction N, the lubriciousliner 36 has a modulus of compression of a magnitude sufficient to allowangular misalignment (i.e., an angular misalignment feature) of theinner race 12 relative to the shaft 23 such that a central axis C ofshaft 23 is displaced or misaligned from the axis B of bore 22 by amisalignment angle α. As a result, shaft 23, lubricious liner 36 andinner race 12 are no longer concentric. In one embodiment, themisalignment angle α is from about one degree to about two degrees. Inanother embodiment, the misalignment angle α is from about one degree toabout ten degrees. In one embodiment, the misalignment angle α is up toabout 15 degrees. Referring to FIG. 4A, the lubricious liner 36surrounds the shaft 23 and has a substantially equal thickness W1, W1′ afull 360° around exterior surface 25 between first end 36C and secondend 36D. Lubricious liner 36 has a modulus of compression of a magnitudesufficient to allow sufficient compression of a width W1 of the linerand correspondingly allow sufficient expansion of width W1′ such thatlubricious liner inner liner-surface 36B remains disposed on exteriorsurface 25 of shaft 23 and lubricious liner exterior liner-surface 36Aremains disposed on inner surface 18 of bore 22 of inner race 12. Assuch, lubricious liner inner liner-surface 36B remains in full contactwith exterior surface 25 of shaft 23 and lubricious liner exteriorliner-surface 36A remains in full contact with inner surface 18 of bore22 of inner race 12. As shown in FIG. 4B, in one embodiment, a portionof width W1 is compressible at the first end 36C to a width W2 andanother portion of width W1′ is correspondingly expandable to a widthW3. At the second end 36D, a portion of the width W1 is compressible towidth W2 and another portion of the width W1′ is expandable to width W3.In one embodiment, a portion of width W1 is compressible to width W2 andanother portion of width W1′ is expandable to width W3 up to a range ofabout 10% of width W1. In one embodiment, a portion of width W1 iscompressible to width W2 and another portion of width W1′ is expandableto width W3 up to a range of about 25% of width W1. In one embodiment, aportion of width W1 is compressible to width W2 and another portion ofwidth W1′ is expandable to width W3 up to a range of about 50% of widthW1.

The lubricious liner 36 includes polytetrafluoroethylene (PTFE). ThePTFE may be in fiber form and woven with fabrics, such as, but notlimited to, cotton, polyester, glass fiber, carbon fiber, nylon, aramidmaterials such as NOMEX® and KEVLAR® manufactured by DuPont, andcombinations of the foregoing. When the PTFE is woven with fabric, thefabric may be set in a thermosetting resin or thermoplastic resin.Examples of thermosetting resins include, but are not limited to,phenolic resins, polyester resins, epoxy resins, urethane resins,polyurethane resins, polyimide resins, and the like. In an alternativeembodiment, the lubricious liner 36 includes the woven PTFE fiber andchopped PTFE fibers in addition to the other fibers and resins listedabove. In yet another embodiment, the lubricious liner 36 includeschopped PTFE fibers in addition to the other fibers and resins listedabove and does not include the woven PTFE fiber.

In another embodiment, the lubricious liner 36 could be molded to orinjected and adhered onto the inner surface 18 defining the bore 22. Insuch an embodiment, the lubricious liner 36 includes a thermosettingresin, such as a phenolic resin, a polyester resin, an epoxy resin, aurethane resin, a polyurethane resin, a polyimide resin, or the like,which is mixed with any one or a combination of fibers such as PTFE,cotton, polyester, glass fiber, carbon fiber, nylon, and aramid fiberssuch as NOMEX® and KEVLAR®.

The present invention is not limited to a bearing assembly comprisingtwo rows of balls, as indicated above. As shown in FIGS. 5-7, thebearing assembly may include rolling elements generally know as rollersof any shape including spherical rollers or balls, convex rollers orbarrel rollers, concave rollers or hourglass rollers, cylindricalrollers, tapered rollers, etc. In each type of bearing assembly, therolling element bearings may have one or two rows of rolling elements.

As shown in FIG. 5, a bearing assembly 110 may comprise an inner race112 located in an outer race 114 with a plurality of rolling elements orballs 116 located therebetween in a single row. As with the bearingassembly of FIG. 1, the inner race 112 is a ring defined by inner andouter surfaces, the inner surface defining a bore 122 extendingtherethrough, the bore being located substantially concentrically aboutan axis F. A lubricious liner 136 is disposed on the inner surfacedefining the bore 122. In one embodiment, bearing assembly 110 includesa seal 130 positioned across the interface of the inner race 112 and theouter race 114 to inhibit the ingress of debris and contaminants intothe bearing assembly. The bearing assembly 110 may include two seals 130positioned generally opposite one another on opposing sides of thebearing assembly. Retaining rings 132 are employed on the outer race 114on one side of the seals 130 to secure the seal in place.

As shown in FIG. 6, in one embodiment a bearing assembly 210 includes aninner race 212 located in an outer race 214 with a plurality of rollingelements or barrel rollers 216 (i.e., convex rollers) locatedtherebetween in a single row. As with the bearing assembly of FIG. 1,the inner race 212 is a ring defined by inner and outer surfaces, theinner surface defining a bore 222 extending therethrough, the bore beinglocated substantially concentrically about an axis G. In one embodimentand as shown in FIG. 6, the outer race 214 is integrally formed with alinkage assembly 240, such as for example a flap hinge arm 40 as furtherdescribed below with reference FIG. 9. A lubricious liner 236 isdisposed on the inner surface defining the bore 222. In one embodiment,bearing assembly 210 includes a seal 230 positioned across the interfaceof the inner race 212 and the outer race 214 to inhibit the ingress ofdebris and contaminants into the bearing assembly. The bearing assembly210 may include two seals 230 positioned generally opposite one anotheron opposing sides of the bearing assembly. Retaining rings 232 areemployed on the outer race 214 on opposing sides of the seals 230 tosecure the seals in place.

As shown in FIG. 7, in one embodiment a bearing assembly 310 includes aninner race 312 located in an outer race 314 with a plurality of rollingelements or hourglass rollers 316 (i.e. concave curvature which meansthe outer raceways correspondingly are convex) located therebetween in asingle row. As with the bearing assembly of FIG. 1, the inner race 312is a ring defined by inner and outer surfaces, the inner surfacedefining a bore 322 extending therethrough. In one embodiment and asshown in FIG. 7, the outer race 314 is integrally formed with a linkageassembly 340, such as for example flap hinge arm 40 as further describedbelow with reference FIG. 9. A lubricious liner 336 is disposed on theinner surface defining the bore 322. In one embodiment, bearing assembly310 includes a seal 330 positioned across the interface of the innerrace 312 and the outer race 314 to inhibit the ingress of debris andcontaminants into the bearing assembly. The bearing assembly 310 mayinclude two seals 330 positioned generally opposite one another onopposing sides of the bearing assembly. Retaining rings 332 are employedon the outer race 314 to secure the seals in place.

As shown in FIG. 8, in one embodiment a bearing assembly 410 includes aninner race 412 located in an outer race 414 with a plurality of rollingelements or cylindrical rollers 416 located therebetween in a singlerow. As with the bearing assembly of FIG. 1, the inner race 412 is aring defined by inner and outer surfaces, the inner surface defining abore 422 extending therethrough. In one embodiment and as shown in FIG.8, the outer race 414 is integrally formed with a linkage assembly 440,such as for example flap hinge arm 40 as further described below withreference FIG. 9. A lubricious liner 436 is disposed on the innersurface defining the bore 222. In one embodiment, bearing assembly 410includes a seal 430 positioned across the interface of the inner race412 and the outer race 414 to inhibit the ingress of debris andcontaminants into the bearing assembly. The bearing assembly 210 mayinclude two seals 230 positioned generally opposite one another onopposing sides of the bearing assembly. Retaining rings 432 are employedon the outer race 414 on opposing sides of the seals 430 to secure theseals in place.

As with the lubricious liner 36 described above with reference to thebearing assembly 10, the lubricious liners 136, 236, 336 and/or 436 maybe PTFE in fiber form and woven with fabrics, such as, but not limitedto, cotton, polyester, glass fiber, carbon fiber, nylon, or aramidmaterials with or without thermosetting resin or thermoplastic resin.Also, the PTFE fiber may be woven or chopped. Furthermore, the materialof the lubricious liners 136, 236, 336 and/or 436 may be molded orinjected as desired for the application at hand.

As shown in FIG. 9, one exemplary embodiment of a flap hinge arm for afixed wing aircraft is designated generally by the reference number 40and is hereinafter referred to as “flap hinge arm 40.” The flap hingearm 40 is defined by an arm 42 having the bearing assembly 10 mounted onone end 42A thereof and a connecting rod 44 pivotally coupled to anopposing end 42B of the arm. As illustrated, the connecting rod 44includes a link apparatus 46 having a spherical plain bearing 47 mountedtherein. The present invention is not limited to the connecting rod 44having the link apparatus 46 and the spherical plain bearing 47,however, as any suitable bearing assembly may be associated with theconnecting rod. The present invention is also not limited to the bearingassembly 10 being mounted in the flap hinge arm 40, however, as thebearing assembly 110 may also be mounted therein. At the end of aconnecting rod, a rod end is typically mounted. This rod end can beattached to the connecting rod by a threaded or welded connection, orany other suitable means. An outer race can be mounted in the rod endeye with a Grumman groove, a press fit, or other suitable means. Insteadof an outer race, the inner surface of the rod end eye can be used asthe outer raceway (i.e. no separable outer race) by suitable heattreatment and machining (hard turning, grinding, or the like).

As shown in FIG. 10, the inner race 12 of the bearing assembly 10 may beintegral with the arm 42 and elongated in a direction transverse to amajor axis G through the arm. In such an embodiment, the bore 22 withthe lubricious liner 36 extends transverse to the major axis H forreceiving a shaft, for example shaft 23 having exterior surface 25 whichengages the lubricious liner 36. The two outer races 14 are positionedproximate the ends of the elongated inner race 12, each outer race 14being mountable as desired to rotatably support the arm 42 in a fixedwing aircraft.

As shown in FIGS. 11 and 12, the flap hinge arm 40 is mounted aft of aspar 48 in a wing 50 of a fixed wing aircraft. The bearing assembly 10of the flap hinge arm 40 is mounted in ribbing 49 or the like aft of thespar 48. Referring to FIG. 11, the flap hinge arm 40 is in an extendedposition that allows a flap 54 to which the flap hinge arm is coupled toextend out of an opening 56 at the rearward-facing surface of the wing50. The flap 54 is defined by a leading portion 54 a and a trailingportion 54 b linkably coupled to each other via a connecting linkage 58.The connecting linkage 58 is pivotally connected to an extension arm 60pivotally mounted at a pivot point 62 in the wing 50 and pivotallymounted at a pivot point 64 on the leading portion 54 a. The leadingportion 54 a is coupled to a hinged extension lever 66 comprising arearward arm 66 a coupled to a forward arm 66 b at a pivot point 67. Theforward arm 66 b is pivotally coupled to the wing 50 proximate theribbing 49 at a pivot point 69. A support link 70 is also coupled to theforward arm 66 b at a pivot point 71 and to the wing at a pivot point72. The connecting rod 44 of the flap hinge arm 40 is also pivotallyconnected to the forward arm 66 b.

Referring now to FIG. 12, when the flap hinge arm 40 is retracted (thearm 42 is moved in the direction as indicated by arrow 76 in FIG. 11),the hinged extension lever 66 is pivoted at pivot point 69 and pulledforward, thereby causing the forward arm 66 b and the rearward arm 66 ato fold at pivot point 67. In doing so, the flap 54 is pulled into theopening 56 in the rearward-facing surface of the wing 50.

Although this invention has been shown and described with respect to thedetailed embodiments thereof, it will be understood by those of skill inthe art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of theinvention. In addition, modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodimentsdisclosed in the above detailed description, but that the invention willinclude all embodiments falling within the scope of the foregoingdescription.

What is claimed is:
 1. A bearing assembly (10, 110, 210, 310, 410)comprising: an outer race (14, 114, 214, 314, 414) having an innersurface (26) defining a concave contour; an inner race (12, 112, 212,312, 412) positioned in the outer race (14, 114, 214, 314, 414), theinner race (12, 112, 212, 312, 412) having an inner surface (18)defining a bore (22) therethrough and an outer surface (20) defining atleast one groove (17) circumscribing the outer surface (20); a pluralityof rolling elements (16, 116, 216, 316, 416) rollably located in the atleast one groove (17) and in rolling contact with the inner surface (26)of the outer race (14, 114, 214, 314, 414); and characterized by: alubricious liner (36, 136, 236, 336, 436) having an inner liner-surface(36A) and an exterior liner-surface (36B), the exterior liner-surface(36B) being disposed on the inner surface (18) defining the bore (22),the lubricious liner (36, 136, 236, 336, 436) having at least one of: amodulus of compression of a magnitude sufficient to allow misalignmentof the inner liner-surface (36A) relative to the exterior liner-surface(36B) in response to a force applied thereto; and a coefficient offriction of a magnitude sufficient to prevent relative motion betweenthe inner race (12, 112, 212, 312, 412) and a shaft (23) extendingthrough the bore (22) of the inner race (12, 112, 212, 312, 412) duringa first operating condition and to allow relative motion between theinner race (12, 112, 212, 312, 412) and the shaft (23) during a secondoperating condition.
 2. The bearing assembly (10, 110, 210, 310, 410) ofclaim 1, wherein the outer surface (20) of the inner race (12, 112, 212,312, 412) comprises a plurality of grooves (17) in which the pluralityof rolling elements (16, 116, 216, 316, 416) is located.
 3. The bearingassembly (10, 110, 210, 310, 410) of claim 2, wherein the plurality ofrolling elements (16, 116, 216, 316, 416) is selected from a groupconsisting of spherical rollers, convex rollers, concave rollers andcylindrical rollers.
 4. The bearing assembly (10, 110, 210, 310, 410) ofclaim 1, further comprising a seal (30, 130, 230, 330, 430) secured tothe outer race (14, 114, 214, 314, 414) and positioned across theplurality of rolling elements (16, 116, 216, 316, 416) to engage asurface of the inner race (12, 112, 212, 312, 412).
 5. The bearingassembly (10, 110, 210, 310, 410) of claim 1, wherein the plurality ofrolling elements (16, 116, 216, 316, 416) are made from a materialselected from the group consisting of stainless steel and corrosionresistant nitrided steel.
 6. The bearing assembly (10, 110, 210, 310,410) of claim 1, wherein the outer race (14, 114, 214, 314, 414) and theinner race (12, 112, 212, 312, 412) are made from a material selectedfrom the group consisting of stainless steel, tungsten steel, andcorrosion resistant nitrided steel.
 7. The bearing assembly (10, 110,210, 310, 410) of claim 1, wherein the lubricious liner (36, 136, 236,336, 436) comprises PTFE.
 8. The bearing assembly (10, 110, 210, 310,410) of claim 7, wherein the PTFE is in fiber form and woven with afabric selected from the group consisting of cotton, polyester, glassfiber, carbon fiber, nylon, aramid material, and combinations of theforegoing materials.
 9. The bearing assembly (10, 110, 210, 310, 410) ofclaim 8, wherein the fabric is set in a thermosetting resin orthermoplastic resin.
 10. The bearing assembly (10, 110, 210, 310, 410)of claim 1 wherein the concave contour of the inner surface (26) of theouter race (14, 114, 214, 314, 414) allows for the inner race (12, 112,212, 312, 412) to be misaligned relative to the outer race (14, 114,214, 314, 414) by up to about 45 degrees.
 11. The bearing assembly (10,110, 210, 310, 410) of claim 1 wherein a shaft is disposed in the boreof the inner race (12, 112, 212, 312, 412) and the shaft is misalignedrelative to the inner race (12, 112, 212, 312, 412) by up to about 15degrees.
 12. A flap hinge arm (40) of a fixed wing aircraft, comprising:an arm (42); a connecting rod (44) pivotally connected to the arm (42)and pivotally connectable to a flap (54); and a bearing assembly (10,110, 210, 310, 410) positioned on the arm and connectable to a wing ofthe fixed wing aircraft, the bearing assembly comprising, an outer race(14, 114, 214, 314, 414) having an inner surface (26) defining a concavecontour; an inner race (12, 112, 212, 312, 412) positioned in the outerrace (14, 114, 214, 314, 414), the inner race (12, 112, 212, 312, 412)having an inner surface (18) defining a bore (22) therethrough and anouter surface (28) defining at least one groove (17) circumscribing theouter surface (28); a plurality of rolling elements (16, 116, 216, 316,416) rollably located in the at least one groove and in rolling contactwith the inner surface (26) of the outer race (14, 114, 214, 314, 414);and characterized by a lubricious liner (36, 136, 236, 336, 436) havingan inner liner-surface (36A) and an exterior liner-surface (36B), theexterior liner-surface (36B) being disposed on the inner surface (18)defining the bore (22), the lubricious liner (36, 136, 236, 336, 436)having at least one of: a modulus of compression of a magnitudesufficient to allow misalignment of the inner liner-surface (36A)relative to the exterior liner-surface (36B) in response to a forceapplied thereto, and a coefficient of friction of a magnitude sufficientto prevent relative motion between the inner race (12, 112, 212, 312,412) and a shaft extending through the bore of the inner race (12, 112,212, 312, 412) during a first operating condition and to allow relativemotion between the inner race (12, 112, 212, 312, 412) and the shaftduring a second operating condition.
 13. The flap hinge arm (40) of afixed wing aircraft of claim 12, further comprising a seal secured tothe outer race (14, 114, 214, 314, 414) and positioned across theplurality of rolling elements (16, 116, 216, 316, 416) to engage asurface of the inner race (12, 112, 212, 312, 412).
 14. The flap hingearm (40) of a fixed wing aircraft of claim 12, wherein the plurality ofrolling elements (16, 116, 216, 316, 416) are made from a materialselected from the group consisting of stainless steel and corrosionresistant nitrided steel.
 15. The flap hinge arm (40) of a fixed wingaircraft of claim 12, wherein the outer race (14, 114, 214, 314, 414)and the inner race (12, 112, 212, 312, 412) are made from a materialselected from the group consisting of stainless steel, tungsten steel,and corrosion resistant nitrided steel.
 16. The flap hinge arm (40) of afixed wing aircraft of claim 12, wherein the lubricious liner (36, 136,236, 336, 436) comprises PTFE.
 17. The flap hinge arm (40) of a fixedwing aircraft of claim 16, wherein the PTFE is in fiber form and wovenwith a fabric selected from the group consisting of cotton, polyester,glass fiber, carbon fiber, nylon, aramid material, and combinations ofthe foregoing materials.
 18. The flap hinge arm (40) of a fixed wingaircraft of claim 17, wherein the fabric is set in a thermosetting resinor thermoplastic resin.
 19. The flap hinge arm (40) of a fixed wingaircraft of claim 17, wherein the plurality of rolling elements (16,116, 216, 316, 416) is selected from a group consisting of sphericalrollers, convex rollers, concave rollers and cylindrical rollers.